Froth flotation of copper sulfide ores



United States FROTH FLOTATION OF COPPER SUL'FIDE ORES No Drawing. Application August 20, 1957 Serial No. 679,148

7 Claims. (Cl. 209-166) This invention relates, in general, to the concentration of ores. More particularly, the invention contemplates the provision of an improved process for the froth flotation of sulfide ores, and a new type of flotation reagent for use in such flotation operations.

The invention is based, in part, on my discovery that dialkyl thiophosphoryl bromides, as represented in general by the following structural formula, are highly eflective flotation reagents and may be employed to great advantage for the recovery of copper values from sulfide ores and partially oxidized sulfide ores:

RO/ \B! wherein R and R each represent an alkyl radical.

The process of the invention may be practiced in conjunction with reagents of the general class defined above which carry either the same or mixed alkyl substituents within the R-R' positions, and the actual alkyl substitution may consist of members of any convenient chain length. In actual practice, however, since those compounds containing common substituent groups from among the lower alkyl radicals are relatively less expensive to produce and are as equally eflective for the purpose intended as the higher homologues or members of mixed alkyl substitution, I prefer to employ such bissubstituted lower alkyl reagents. Furthermore, the reagents of the invention need not be especially pure, but entirely satisfactory results can be obtained with relatively crude products.

Significantly, the flotation reagents utilized in the process of the invention are substantially more efficient in the acid circuit flotation of copper sulfide ores and partially oxidized copper sulfide ores, than are closely related reagents heretofore employed in such operations. For example, the flotation reagents are superior to the dialkyl thiophosphoryl chlorides, although such superiority was not to be expected on the basis of any prior teachings available within the field of this invention.

The process of the invention finds particular application in the treatment of pulp products produced in operations of the leach-precipitation-float type, wherein an ore is initially subjected to acid leaching to dissolve its soluble oxidized constituents, followed by treatment with metallic iron, such as sponge iron, to eflect precipitation of the dissolved copper values as metallic cement copper. The resulting pulp of sulfide ore and cement copper is then subjected to a froth flotation operation in the presence of a dialkyl thiophosphoryl bromide for the separation and recovery of a concentrate and tailing product.

It is believed that the process of the invention may be best understood by reference to the following specific examples showing the application of the foregoing principles and procedures in conjunction with a typical flotation reagent of the general class described, as compared with the results obtained through use of conventional reagents under substantially identical operating conditions:

2,901,107 Patented Aug. 25, 1959 Example I A sulfide ore of the composition with respect to copper indicated below, was ground in water to form an aqueous pulp which was subjected to a froth flotation operation in the presence of the two separate reagents also indicated below, under substantially identical operating conditions, with the production of a concentrate and tailing product of the analyses shown:

Test

Percent On Heads 1. 045 Q l. 045 5.59 6.27 Percent Cu Tails 0.170 0.129

Reagent compositions (pounds per ton):

Sulfuric acid 8.0 Pine oil 0.08 Diethyl thiophosphoryl chloride (test A) 0.10 Diethyl thiophosphoryl bromide (test B) 0.10

Example 11 An aqueous pulp containing sulfide ore and cement copper resulting from leach-precipitation treatment of a partially oxidized sulfide ore of the composition with respect to copper indicated below, was subjected to a froth flotation operation in the presence of the two separate reagents also indicated below, with the production of a concentrate and tailing product of the analyses shown:

Example 111 An aqueous pulp containing sulfide ore and cement copper resulting from leach-precipitation treatment of a partially oxidized sulfide ore of the composition with respect to copper indicated below, was subjected to a froth flotation operation in the presence of the two separate reagents also indicated below, with the production of a concentrate and tailing product of the analyses shown:

Test

Percent Cu Heads... 1. 250 1. 250 Percent Cu Oonc 4. 5. 08 Percent Cu Tails. 0.151 0.107

Reagent compositions (pounds per ton):

Sulfuric acid 12.0

Pine oil 0.10

Diethyl thiophosphoryl chloride (test A) 0.25

Diethyl thiophosphoryl bromide (test B) 0.25

Having thus described the subject of my invention, what it is desired to secure by Letters Patent is:

1. Process for the concentration of copper sulfide ores by froth flotation that comprises effecting the froth flotation in the presence of a flotation reagent selected from the group of compounds represented by the formula:

R-O s -O/ Br wherein R and R' are members selected from the group consisting of lower alkyl radicals, and recovering a froth concentrate relatively rich in copper and a froth tailing relatively poor in. copper.

2. The process. as claimed in claim 1, wherein said froth flotation is effected with an aqueous pulp containing copper sulfide ore and cement copper resulting from preliminary leach precipitation treatment of a copper sulfide ore.

3. The process as claimed in claim 1, wherein the flotation is effected in acid circuit.

4. The process as claimed in claim 1, wherein said froth flotation is effected in acid circuit with an aqueous pulp containing copper sulfide ore and cement copper resulting from preliminary leach precipitation treatment of a copper sulfide ore.

5. Process for the concentration of copper sulfide ores by froth flotation that comprises effecting said froth flotation in the presence of diethyl thiophosphoryl bromide, and recovering a froth concentrate relatively rich in copper and a froth tailing relatively poor in copper.

6. Process for the concentration of copper sulfide ores by froth flotation that comprises effecting said froth flotation in the presence of diethyl thiophosphoryl bromide with an aqueous pulp containing copper sulfide ore and cement copper resulting from preliminary leach-precipitation. treatment of a copper sulfide ore, and recovering a froth concentrate relatively rich in copper and a froth tailing relatively poor in copper.

7. Process for the concentration of copper sulfide ores by froth flotation that comprises effecting said froth flotation in the presence of diethyl thiophosphoryl bromide in acid circuit with an aqueous pulp containing copper sulfide ore and cement copper resulting from preliminary leach-precipitation treatment of a copper sulfide ore, and recovering a froth concentrate relatively rich in copper and a froth tailing relatively poor in copper.

References Cited in the file of this patent UNITED STATES PATENTS 

1. PROCESS FOR THE CONCENTRATION OF COPPER SULFIDE ORES BY FROTH FLOTATION THAT COMPRISES EFFECTING THE FROTH FLOTATION IN THE PRESENCE OF A FLOTATION REAGENT SELECTED FROM THE GROUP OF COMPOUNDS REPRESENTED BY THE FORMULA: 